-- "Heading into next week's Republican convention, Mitt Romney remains within striking distance of President Barack Obama but faces steep challenges in inducing voters to warm up to him as a candidate, a new Wall Street Journal/NBC News poll has found. Mr. Romney's choice of Rep. Paul Ryan as his running mate has stirred excitement within the GOP that he can defeat the president. But the poll found little evidence the pick will affect the election, beyond helping unify Mr. Romney's conservative base."

-- "For all the attention it got, Republican Mitt Romney's selection of Rep. Paul Ryan of Wisconsin as his running mate has not altered the race against President Barack Obama. The campaign remains neck and neck with less than three months to go, a new AP-GfK poll shows."

Both national polls of registered voters show races with differences that are well within their margins of error:

-- The AP-GfK survey shows the Obama/Biden ticket with 47 percent support to Romney/Ryan's 46 percent. The Associated Press writes that is "not much changed from a June AP-GfK survey, when the split was 47 percent for the president to 44 percent for Romney."

-- In the Wall Street Journal/NBC News poll, Obama/Biden led Romney/Ryan 48 percent to 44 percent — "about the same as a month earlier."

As always, it's important to remember that these types of polls are snapshots in time that ask voters which candidate they support today. Election Day, of course, isn't until Nov. 6 and a lot can change between now and then.